The present invention relates to new processes for the preparation of 6,11-dihydro-11-oxodibenz[b,e]oxepin-2-acetic acid and the corresponding 3-isomer. 6,11-Dihydro-11-oxodibenz[b,e]oxepin-acetic acids produced by the processes of the invention can be represented by the formula: ##STR5## in which the CH.sub.2 -COOH moiety is in the 2- or 3-position. These compounds are known to exhibit antiinflammatory and analgesic activity. Processes of this invention also produce certain intermediate or precursor compounds, which are novel and are useful for the production of the 6,11-dihydro-11-oxodibenz[b,e]oxepinacetic acids. Of particular interest are the processes as they relate to the preparation of 6,11-dihydro-11-oxodibenz[b,e]oxepin-2-acetic acid.